Articulating front axle mower

ABSTRACT

In a riding mower having a frame supported on front and rear wheels, a mower deck supported beneath the frame, a chair on said frame and a source of motive power also supported on said frame and including an improved suspension system with an articulating front axle that substantially isolates the front wheels from the frame of the lawnmower to thereby dampen vibrations transmitted to the operator as the vehicle traverses the ground.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. patent application Ser. No.15/708,307 titled “Articulating Front Axle Mower” which was filed onSep. 19, 2017 and claims priority to U.S. Provisional Patent ApplicationNo. 62/396,661 filed on Sep. 19, 2016 and priority to U.S. ProvisionalPatent Application No. 62/400,321 filed on Sep. 27, 2016, each of whichare incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not Applicable.

RESERVATION OF RIGHTS

A portion of the disclosure of this patent document contains materialwhich is subject to intellectual property rights such as but not limitedto copyright, trademark, and/or trade dress protection. The owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure as it appears in the Patent and TrademarkOffice patent files or records but otherwise reserves all rightswhatsoever.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to riding mowers and, moreparticularly, to an improved suspension system on such mowers or thelike. Known art can be found in U.S. Class 280, subclass 124 and inother classes and subclasses.

2. Description of the Known Art

Those skilled in the art will appreciate that riding mowers have been astaple for maintaining residential yards, commercial lawns, golf coursesand highway rights of way for many years. They are seen moving alonggrass in many settings including grassy center dividers and along thesides of roads in rough, sometimes rocky terrain, and in all sorts ofattitudes from flat and level to severe side hills.

In many instances, an operator may be in the seat for hours, and evenwith a kidney belt, will suffer considerable discomfort and, in somecases, injury from traversing rough ground at speed. Indeed, it is notinconceivable that the constant bouncing and jarring could cause anoperator to lose control, resulting in damage to the operator and othersand also to the equipment as well.

The underlying purpose and function of the present invention is toprovide an element of relief to an operator and increased vehiclecontrol. The invention disclosed in U.S. Pat. No. 7,708,292 issued toFoster deals with these issues. While this invention works well for itsintended purpose, an improved system that uses an articulating frontaxle that also improves vehicle stability while also promoting operatorcomfort would be desirable.

Most of the other known riding mowers in use today have their wheelsaffixed directly to the frame of the mower. In the late '90s, Ferrisfiled an application for a suspension system for riding mowers. Theapplication claims priority based on provisionals, at least one of whichdates back to 1996, and was divided and one of thosecontinuations-in-part issued as Ferris et al. U.S. Pat. No. 6,460,318.The patent features a four bar mechanism relatively common in automotivesuspensions.

Known art which may be relevant to the present invention includes thefollowing patents with their abstracts, the teachings of which areincorporated by reference.

Gordon U.S. Pat. No. 6,170,242 is yet another patent assigned to FerrisIndustries and claims priority under a 1997 provisional, which is alsoclaimed under the earlier mentioned Ferris et al. patent. Gordon, likeFerris et al., features a four bar mechanism.

A very early patent featuring a rubber bumper between two elements in anautomotive structure is found in Hickman U.S. Pat. No. 3,737,174.

Several other patents offer variations on the same theme. See, forexample, Dunlap et al. U.S. Pat. No. 3,669,467, which has additionalbuffering devices, such as springs, leaf or coil, and shock absorbingdevices. Dunlap has a pair of cushions, but also uses a pair of rods 32and 34, which attach directly to the frame rail.

Krakowiak et al. U.S. Pat. No. 5,979,920, uses the simple bumper betweenthe frame rail and a leaf spring. This is a device which is common onmany of the earlier motor vehicles.

Merkle U.S. Pat. No. 4,310,717, uses what he refers to as an elastomericspring, again, between the frame rail and what he refers to as a websection which holds the axle upon which the wheel is connected. Itappears in the drawing that there may be a shock absorber in the middleof this assembly.

Bonzer et al. U.S. Pat. No. 4,559,669, employs a resilient buffer 19 fora caster assembly. Heitzman U.S. Pat. No. 5,899,470 uses a couple ofresilient buffers as part of a system for adjusting camber and caster.It is evident from these patents that using an elastomeric as a springor shock absorber is not new in the art. All of these references seek,to a greater or lesser extent, some modulation of the amplitude andfrequency of shock transmitted through a wheel of a vehicle, but areunsuited for a riding mower.

Also, commercially available equipment and components may be relevant,including hollow metal frames, elastomeric bushings or cushions and thelike. Such equipment may be used in implementing an exemplary embodimentin accordance with the present invention.

None of these references, either singly or in combination, disclose orsuggest the present invention. It is desirable to have an improvedlawnmower to address the perceived shortcomings of the known art.

While it is evident from past attempts that suspension systems forlawnmowers are desirable, the known art is limited in its teaching andutilization, and an improved system is needed to overcome theselimitations. An improved suspension system should provide a simple andefficient system for meeting the various needs of the users and thelike.

SUMMARY OF THE INVENTION

The present invention addresses the perceived needs in the known artdiscussed above. In this regard, the present invention substantiallyfulfills this need. The suspension system for lawnmower may beadvantageously used with zero-turn lawnmowers or others using transaxlescombined with hydraulic pumps for motive power and the like. Theconventional rigid front axle is replaced by an articulating front axlewith arms that are dampened by at least one pillow interposed betweenthe frame and each front caster wheel with each pillow being of aresilient material for absorbing shock and vibration resulting from awheel contacting irregularities in the terrain traversed thereby.

In one exemplary embodiment in accordance with the present invention animproved suspension system with an articulating front axle is providedthat substantially isolates the front wheels from the frame of thelawnmower to thereby dampen vibrations transmitted to the operator asthe vehicle traverses the ground.

The apparatus of the invention is capable of receiving additional,optional features which are not a part of the present invention. Forexample, a purchaser or user may specify an optional mulcher or baggeror the like for a lawnmower. Other optional features, some of which maybe illustrated herein, may or may not be included with apparatusincorporating the basic aspects of present invention.

In addition to providing the features and advantages referred to above,it is an object of the present invention to provide an improvedsuspension system for lawnmower.

A basic object of the present invention is to provide a more stablelawnmower.

Yet another object of the present invention is to enhance user comfort.

A related object of the present invention is to provide a saferlawnmower.

These and other objects and advantages of the present invention, alongwith features of novelty appurtenant thereto, will appear or becomeapparent by reviewing the following detailed description of theinvention in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the following drawings, which form apart of the specification andwhich are to be construed in conjunction therewith, and in which likereference numerals have been employed throughout wherever possible toindicate like parts in the various views:

FIG. 1 is a perspective view of a riding mower in accordance with anembodiment of the present invention;

FIG. 2 is a slightly enlarged perspective view of the front of the mowerwith the front articulating axle shown and with the mower deck removedfor clarity;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is an elevational view taken from the side with the opposite sidebeing a mirror image thereof;

FIG. 6 is an elevational view taken generally from the rear thereof;and,

FIG. 7 is an elevational view taken generally from the front and similarto FIG. 2 but showing movement.

DETAILED DESCRIPTION OF THE INVENTION

The present invention addresses the perceived needs in the known artdiscussed above. In this regard, the present invention substantiallyfulfills this need. The improved suspension system for lawnmowerincludes an articulating front axle with a vibration damping system thatmakes for a less bumpy ride for the operator on the mower.

In one exemplary embodiment in accordance with the present invention andshown in FIGS. 1-7, an improved riding mower 11 is illustrated. Themower 1 has a frame 16 supported by a pair of forward wheel assemblies18 and rear wheel assemblies 20.

The frame 16 supports a mower deck 25, and a chair 27 is provided for adriver, with a pair of steering arms 29 within easy reach. A motorcompartment 32 rides on the frame and provides motive power to the mowerthrough right and left integrated hydrostatic transaxles that driveright and left rear wheels 72 in response to operator manipulation ofcontrol handles 29.

One important feature of the present invention is the provision of themower 11 which has enhanced comfort and less fatigue for the driver, allof which increases the ability of the driver to control the mower, evenin unusual attitudes resulting from irregularities in the terrain, andover extended periods of operation, and particularly where terrainchanges are abrupt. In accomplishing its objectives, both forward andrear systems of vibration control are interposed between each of thesupporting wheel assemblies and the frame of the mower.

It is a feature of the present invention that a front suspension systemis provided with vibration damping capability. Referring to FIGS. 2-7,each articulating suspension arm 40, 50 supports two spaced apart frontcastered wheels 18; the articulating suspension arms are mountedgenerally transverse to the longitudinal axis of the mower 11.

The independently, articulating suspension system 30 includes a left andright articulating arm 40, 50 that each has an inner terminus 42, 52that are proximate each other. The terminuses 42, 52 are captivated bymounting plate 60 with through bolts 62, 64 that are coupled to thefront end of frame 16. The bolts 62, 64 permit pivotal movement ofarticulating arms 40, 50 vertically, both upwardly and downwardly.

The forward end of frame 16 and the leading end of plate 60 effectivelysandwich at least a portion of the articulating arms 40, 50 andespecially terminuses 42, 52 therebetween to prevent lateralarticulating arm movements.

Movement of the front wheels is limited and vibration is dampened by theprovision of damping pillows 81 which are secured between the mountingplate 60 (which is attached to the front end of frame 16) and the innerterminus of each front articulating arm 40, 50. The pivotal movement ofeach articulating arm 40, 50 is shown by arrow 68, which corresponds toan accompanying compression of the affected pillows 81 (FIG. 7).

Each pillow 81 is resilient and may be of any one of several durometersof rubber hardness, or may be of other suitable elastomeric materials,including elastic shells with a liquid or other compressible materialthere within, appropriate to the weight of the mower and the terrain tobe traversed. The pillows define a cushion between the wheel and theframe of the mower, thereby absorbing shock created by the wheel movingover the uneven terrain. Further, each wheel functions independently,i.e., independent of the frame, in order that it may respondindependently to variations in the terrain met by each individual wheel,which may be several feet removed from its companion wheel.

The pillows 81 are positioned between the articulating arms 40, 50 andthe mounting plate 60 and a bolt 85 passes through the mounting plate 60and is secured by the pillow's threads that run along its longitudinalaxis. The pillow is sized to abut the articulating arms 40, 50 and themounting plate 60 above and beneath each, where it is held in place bybolt 85 and the pillow is compressed by an articulating arm 40, 50 dueto the rapid upward movement of a wheel assembly, thereby dampening thatmovement and inhibiting, or at least modulating, transmission of thatmovement to the frame of the mower. The rapid movement resulting fromthe traversing of rocks and other debris is particularly well dampened.

The apparatus of the invention is capable of receiving additional,optional features which are not a part of the present invention. Forexample, a purchaser or user may specify an optional railing or grabbars may be included to facilitate handling of the device duringdeployment. Other optional features, some of which may be illustratedherein, may or may not be included with apparatus incorporating thebasic aspects of present invention.

In describing a preferred embodiment of the invention illustrated in thedrawings, specific terminology has been used for the sake of clarity.However, the invention is not intended to be limited to the specificterms selected, and it is to be understood that each specific termincludes all technical equivalents which operate in a similar manner toaccomplish a similar purpose.

What is claimed is:
 1. A zero-turn-radius (ZTR) riding mower systemcomprising: a frame; a front wheel assembly; a front articulating arm,the front wheel assembly pivotally coupled to the frame by way of thefront articulating arm, and the front articulating arm comprising adistal end coupled to the front wheel assembly and a proximal endpivotally coupled to the frame; and a resilient member disposed betweenthe frame and a proximate portion of the front articulating arm that islocated between a mid-section of the front articulating arm and theproximal end of the front articulating arm.
 2. The system of claim 1,wherein the resilient member is formed of an elastomeric material. 3.The system of claim 1, wherein a first portion of the resilient memberabuts a surface of the frame and wherein a second portion of theresilient member abuts a surface of the front articulating arm.
 4. Thesystem of claim 1, wherein the resilient member is configured to becompressed between the frame and the proximate portion of the frontarticulating arm.
 5. The system of claim 4, wherein the compression ofthe resilient member between the frame and the proximate portion of thefront articulating arm is configured to regulate pivoting of the frontarticulating arm.
 6. The system of claim 1, wherein the resilient memberis coupled to the frame.
 7. The system of claim 6, wherein the resilientmember is coupled to the frame by way of a resilient member fasteningmember having a longitudinal axis that is coincident with a longitudinalaxis of the resilient member.
 8. The system of claim 7, wherein theresilient member fastening member comprises a threaded fastener that isfastened to complementary threads of the resilient member.
 9. The systemof claim 1, wherein the proximal end of the front articulating arm ispivotally coupled to the frame by way of a front articulating armfastening member that extends through the proximal end of the frontarticulating arm.
 10. The system of claim 9, wherein the frontarticulating arm fastening member comprises a threaded fastener thatextends through the proximal end of the front articulating arm.
 11. Thesystem of claim 1, wherein the proximal end of the front articulatingarm is disposed between vertically oriented members of the frame, andwherein the proximal end of the front articulating arm is pivotallycoupled to the frame by way of a front articulating arm fastening memberthat extends between the vertically oriented members.
 12. The system ofclaim 11, wherein the front articulating arm fastening member comprisesa threaded fastener that extends between the vertically orientedmembers.
 13. The system of claim 11, wherein the frame comprises amounting plate that comprises the vertically oriented members of theframe, and wherein the resilient member is disposed between an upperface of the articulating arm and the mounting plate.
 14. The system ofclaim 1, further comprising: a second front wheel assembly; a secondfront articulating arm, the second front wheel assembly pivotallycoupled to the frame by way of the second front articulating arm, andthe second front articulating arm comprising a distal end coupled to thesecond front wheel assembly and a proximal end pivotally coupled to theframe; and a second resilient member disposed between the frame and aproximate portion of the second front articulating arm that is locatedbetween a mid-section of the second front articulating arm and theproximal end of the second front articulating arm.
 15. The system ofclaim 14, wherein the resilient member is formed of an elastomericmaterial, and wherein the second resilient member is formed of anelastomeric material.
 16. The system of claim 14, wherein the resilientmember is configured to be compressed between the frame and theproximate portion of the front articulating arm, and wherein the secondresilient member is configured to be compressed between the frame andthe proximate portion of the second front articulating arm.
 17. Thesystem of claim 16, wherein the compression of the resilient memberbetween the frame and the proximate portion of the front articulatingarm is configured to regulate pivoting of the front articulating arm,and wherein the compression of the second resilient member between theframe and the proximate portion of the second front articulating arm isconfigured to regulate pivoting of the second front articulating arm.18. The system of claim 14, wherein the resilient member is coupled tothe frame, and wherein the second resilient member is coupled to theframe.
 19. The system of claim 18, wherein the resilient member iscoupled to the frame by way of a resilient member fastening memberhaving a longitudinal axis that is coincident with a longitudinal axisof the resilient member, and wherein the second resilient member iscoupled to the frame by way of a second resilient member fasteningmember having a longitudinal axis that is coincident with a longitudinalaxis of the second resilient member.
 20. The system of claim 14, whereinthe proximal end of the front articulating arm is pivotally coupled tothe frame by way of a front articulating arm fastening member thatextends through the proximal end of the front articulating arm, andwherein the proximal end of the second front articulating arm ispivotally coupled to the frame by way of a second front articulating armfastening member that extends through the proximal end of the secondfront articulating arm.
 21. The system of claim 14, wherein the proximalend of the front articulating arm is disposed between verticallyoriented members of the frame, and wherein the proximal end of the frontarticulating arm is pivotally coupled to the frame by way of a frontarticulating arm fastening member that extends between the verticallyoriented members, and wherein the proximal end of the second frontarticulating arm is disposed between the vertically oriented members,and wherein the proximal end of the second front articulating arm ispivotally coupled to the frame by way of a second front articulating armfastening member that extends between the vertically oriented members.22. The system of claim 21, wherein the frame comprises a mounting platethat comprises the vertically oriented members of the frame, wherein theresilient member is disposed between an upper face of the articulatingarm and the mounting plate, and wherein the second resilient member isdisposed between an upper face of the second front articulating arm andthe mounting plate.
 23. The system of claim 14, wherein the resilientmember is formed of an elastomeric material, wherein the secondresilient member is formed of an elastomeric material, wherein theproximal end of the front articulating arm is pivotally coupled to theframe by way of a front articulating arm fastening member that extendsthrough the proximal end of the front articulating arm, wherein theproximal end of the second front articulating arm is pivotally coupledto the frame by way of a second front articulating arm fastening memberthat extends through the proximal end of the second front articulatingarm, wherein the resilient member is configured to be compressed betweenthe frame and the proximate portion of the front articulating arm,wherein the second resilient member is configured to be compressedbetween the frame and the proximate portion of the second frontarticulating arm, wherein the compression of the resilient memberbetween the frame and the proximate portion of the front articulatingarm is configured to regulate pivoting of the front articulating arm,and wherein the compression of the second resilient member between theframe and the proximate portion of the second front articulating arm isconfigured to regulate pivoting of the second front articulating arm.24. A zero-turn-radius (ZTR) riding mower system comprising: a frame; afront wheel assembly; a front articulating arm configured to pivotallycouple the front wheel assembly to the frame, the front articulating armcomprising a distal end configured to couple to the front wheel assemblyand a proximal end configured to pivotally couple to the frame; and aresilient member configured to be disposed between the frame and aproximate portion of the front articulating arm that is located betweena mid-section of the front articulating arm and the proximal end of thefront articulating arm.
 25. The system of claim 24, wherein theresilient member is formed of an elastomeric material.
 26. The system ofclaim 24, wherein a first portion of the resilient member is configuredto abut a surface of the frame and wherein a second portion of theresilient member is configured to abut a surface of the frontarticulating arm.
 27. The system of claim 24, wherein the resilientmember is configured to be compressed between the frame and theproximate portion of the front articulating arm.
 28. The system of claim27, wherein the compression of the resilient member between the frameand the proximate portion of the front articulating arm is configured toregulate pivoting of the front articulating arm.
 29. The system of claim24, wherein the resilient member is configured to be coupled to theframe.
 30. The system of claim 29, wherein the resilient member isconfigured to be coupled to the frame by way of a resilient memberfastening member having a longitudinal axis that is coincident with alongitudinal axis of the resilient member.
 31. The system of claim 30,wherein the resilient member fastening member comprises a threadedfastener that is configured to fasten to complementary threads of theresilient member.
 32. The system of claim 24, wherein the proximal endof the front articulating arm is configured to be pivotally coupled tothe frame by way of a front articulating arm fastening member thatextends through the proximal end of the front articulating arm.
 33. Thesystem of claim 32, wherein the front articulating arm fastening membercomprises a threaded fastener that is configured to extend through theproximal end of the front articulating arm.
 34. The system of claim 24,wherein the proximal end of the front articulating arm is configured tobe disposed between vertically oriented members of the frame, andwherein the proximal end of the front articulating arm is configured tobe pivotally coupled to the frame by way of a front articulating armfastening member that extends between the vertically oriented members.35. The system of claim 34, wherein the front articulating arm fasteningmember comprises a threaded fastener that is configured to extendbetween the vertically oriented members.
 36. The system of claim 34,wherein the frame comprises a mounting plate that comprises thevertically oriented members of the frame, and wherein the resilientmember is configured to be disposed between an upper face of thearticulating arm and the mounting plate.
 37. The system of claim 24,further comprising: a second front wheel assembly; a second frontarticulating arm, the second front wheel assembly configured topivotally couple to the frame by way of the second front articulatingarm, and the second front articulating arm comprising a distal endconfigured to couple to the second front wheel assembly and a proximalend configured to pivotally couple to the frame; and a second resilientmember configured to be disposed between the frame and a proximateportion of the second front articulating arm that is located between amid-section of the second front articulating arm and the proximal end ofthe second front articulating arm.
 38. The system of claim 37, whereinthe resilient member is formed of an elastomeric material, wherein thesecond resilient member is formed of an elastomeric material, whereinthe proximal end of the front articulating arm is configured to bepivotally coupled to the frame by way of a front articulating armfastening member that extends through the proximal end of the frontarticulating arm, wherein the proximal end of the second frontarticulating arm is configured to be pivotally coupled to the frame byway of a second front articulating arm fastening member that extendsthrough the proximal end of the second front articulating arm, whereinthe resilient member is configured to be compressed between the frameand the proximate portion of the front articulating arm, wherein thesecond resilient member is configured to be compressed between the frameand the proximate portion of the second front articulating arm, whereinthe compression of the resilient member between the frame and theproximate portion of the front articulating arm is configured toregulate pivoting of the front articulating arm, and wherein thecompression of the second resilient member between the frame and theproximate portion of the second front articulating arm is configured toregulate pivoting of the second front articulating arm.